A
bstract
We attempt to build a model that describes the
Fermi
galactic gamma-ray excess (FGCE) within a UV-complete Supersymmetric framework; we find this to be highly non-trivial. At the very least ...a successful Supersymmetric explanation must have several important ingredients in order to fit the data and satisfy other theoretical and experimental constraints. Under the assumption that a
single
annihilation mediator is responsible for both the observed relic density as well as the FGCE, we show that the requirements are not easily satisfied in many TeV-scale SUSY models, but can be met with some model building effort in the general NMSSM with ∼ 10 parameters beyond the MSSM. We find that the data selects a particular region of the parameter space with a mostly singlino lightest Supersymmetric particle and a relatively light CP-odd Higgs boson that acts as the mediator for dark matter annihilation. We study the predictions for various observables within this parameter space, and find that searches for this light CP-odd state at the LHC, as well as searches for the direct detection of dark matter, are likely to be quite challenging. It is possible that a signature could be observed in the flavor sector; however, indirect detection remains the best probe of this scenario.
Gold is an increasingly prominent transition metal in organic synthesis. The air-stable, water-insensitive cationic gold(I) catalysts enable varieties of synthetic transformations with a simple ...reaction setup. However, this increased importance has not coincided with an increase in the application of gold in second-year organic chemistry courses. An experiment is described that includes a gold-catalyzed rearrangement of propargyl alcohols targeted at second-year organic chemistry students. The reaction produces a mixture of E and Z isomers of an enone product that students analyze by 1H NMR spectroscopy to determine the major product.
Perhaps the most important question in particle physics today is whether the boson with mass near 125 GeV discovered at the Large Hadron Collider (LHC) is the Higgs Boson of the Standard Model. Since ...a particularly important property of the Standard Model Higgs is its role in unitarizing W sub(L)W sub(L) scattering, we study the ability of the LHC to probe this process in the case of same-sign W pair production. We find that the use of the matrix element method increases the significance with which the Higgs sector can be probed in this channel. In particular, it allows one to distinguish between a light and heavy Standard Model Higgs in this channel alone with a high degree of significance, as well as to set important limits in the parameter space of the two-Higgs doublet model and the strongly interacting light Higgs model with less than 200 fb super(-1) at the 14 TeV LHC, thus providing crucial information about the putative Higgs boson's role in electroweak symmetry breaking.
Angiotensin-converting-enzyme (ACE) inhibitors not only decrease the production of angiotensin II but also decrease the degradation of bradykinin. In this study, a specific bradykinin-receptor ...antagonist, icatibant acetate (HOE 140), was used to determine the contribution of bradykinin to the short-term effects of ACE inhibition on blood pressure and plasma renin activity in both normotensive and hypertensive subjects.
We compared the hemodynamic, renal, and endocrine effects of captopril alone (25 mg), captopril plus icatibant (100 microg per kilogram of body weight), the angiotensin II subtype 1-receptor antagonist losartan (75 mg), and placebo in 20 subjects with normal blood pressure and 7 subjects with hypertension. The subjects were studied while they were salt depleted (i.e., in balance on a diet in which they were allowed 10 mmol of sodium per day). The drugs were administered on four separate study days in a single-blind, randomized fashion.
The coadministration of icatibant significantly attenuated the hypotensive effect of captopril (maximal decrease in mean arterial pressure for all subjects combined, 10.5+/-1.0 mm Hg, as compared with 14.0+/-1.0 mm Hg for captopril alone; P=0.001), in such a way that the decrease in blood pressure after the administration of captopril plus icatibant was similar to that after the administration of losartan (maximal decrease in mean arterial pressure, 11.0+/-1.7 mm Hg). Icatibant did not alter the renal hemodynamic response to captopril, but it significantly altered the change in plasma renin activity in response to ACE inhibition (-0.4+/-0.4 ng of angiotensin I per milliliter per hour, as compared with 2.0+/-0.7 ng per milliliter per hour for captopril alone; P=0.007). The magnitude of these effects was similar in both the normotensive and the hypertensive subjects, as well as in both the black subjects and the white subjects.
These data confirm that bradykinin contributes to the short-term effects of ACE inhibition on blood pressure in normotensive and hypertensive persons and suggest that bradykinin also contributes to the short-term effects of ACE inhibition on the renin-angiotensin system.
The esterification of long-chain fatty acids in
n-hexane catalyzed by nylon-immobilized lipase from
Candida rugosa has been investigated. Butyl oleate (22 carbon atoms), oleyl butyrate (22 carbon ...atoms) and oleyl oleate (36 carbon atoms) were produced at maximum reaction rates of ≈60 mmol h
−1 g
−1 immobilized enzyme when the substrates were present in equimolar proportions at an initial concentration of 0.6 mol l
−1. The observed kinetic behavior of all the esterification reactions is found to follow a ping-pong bi-bi mechanism with competitive inhibition by both substrates. The effect of the chain-length of the fatty acids and the alcohols could be correlated to some mechanistic models, in accordance with the calculated kinetic parameters.
Different than others: Dimeric rhodium(II) carboxylates uniquely catalyze the 6‐endo‐dig selective hydroamination of propargylguanidines while tranditional π‐Lewis acids are typically 5‐exo‐dig ...selective (see scheme, oct=octanoate). Furthermore, this represents a new role for RhII to activate alkynes for addition chemistry.
Bradykinin stimulates tissue plasminogen activator (tPA) release in isolated perfused animal tissues. The present study tests the hypothesis that bradykinin increases tPA release in humans through ...local effects on the vasculature. Graded doses of sodium nitroprusside (0.8 to 3.2 micrograms/min), acetylcholine (ACh) (7.5 to 60 micrograms/min), and bradykinin (100 to 400 ng/min) were administered intra-arterially in random order in 10 salt-depleted (10 mmol/d of Na) normotensive volunteers. None of the drugs altered mean arterial pressure or heart rate. Forearm blood flow (FBF) was measured by strain-gauge plethysmography. All 3 drugs caused a dose-dependent increase in FBF, although ACh was less potent than either nitroprusside or bradykinin (maximum FBF 7.5+/-2.4 versus 10.0+/-1.5 and 11.9+/-2.1 mL. 100 mL-1. min-1, respectively). Bradykinin caused a significant, dose-dependent increase in venous (effect of dose F=9. 9, P=0.028 by ANOVA), but not arterial (F=0.154, P=0.92) tPA antigen in the infused arm. Thus, net tPA release increased significantly in response to bradykinin (50.6+/-13.3 at the highest dose versus 0. 9+/-0.4 ng. 100 mL-1. min -1 at baseline, P=0.014). In contrast, bradykinin did not affect plasminogen activator inhibitor antigen. Neither nitroprusside nor ACh altered plasma levels of tPA or plasminogen activator inhibitor antigen. Bradykinin increased tPA release across the forearm in the absence of systemic effects. This effect could not be attributed to changes in blood flow because doses of equivalent potency of the vasodilator nitroprusside did not increase tPA. These data demonstrate that bradykinin stimulates tPA release in the human vasculature.
Micellar catalysis has become an important aspect of the chemical industry’s effort to “go green”. However, this chemistry has yet to be fully explored in educational settings such as second-year ...organic chemistry laboratories. Reported herein is a discovery-based nucleophilic aromatic substitution experiment that introduces chemistry students to micellar catalysis, green chemistry, and systems thinking. The students prepare tandem reactions in water to explore how the leaving group identity affects the rate of reaction and how the reaction incorporates principles of green chemistry. The product of the fastest reaction is isolated through recrystallization, and the product’s identity is verified through infrared spectroscopy and melting point analysis.
Angiotensin I–converting enzyme inhibitors (ACEi), which are used to treat common cardiovascular diseases, are associated with a potentially life-threatening adverse reaction known as angioedema ...(AE-ACEi). We have previously documented a significant association between AE-ACEi and low plasma aminopeptidase P (APP) activity. With eight large pedigrees, we hereby demonstrate that this quantitative trait is partially regulated by genetic factors. We tested APP activity using a variance-component QTL analysis of a 10-cM genomewide microsatellite scan enriched with seven markers over two candidate regions. We found significant linkage (LOD = 3.75) to a locus that includes the
XPNPEP2 candidate gene encoding membrane-bound APP. Mutation screening of this QTL identified a large coding deletion segregating in one pedigree and an upstream single-nucleotide polymorphism (C–2399A SNP), which segregates in the remaining seven pedigrees. Measured genotype analysis strongly suggests that the linkage signal for APP activity at this locus is accounted for predominantly by the SNP association. In a separate case-control study (20 cases and 60 controls), we found significant association of this SNP to ACEi-induced AE (
P=.0364). In conclusion, our findings provide supporting evidence that the C-2399A variant in
XPNPEP2 is associated with reduced APP activity and a higher incidence of AE-ACEi.
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